I've just released version 0.28 of Obnam,
my backup application. The relevant part of NEWS:

force-lock should now remove all locks.

Out-of-space errors in the repository now terminate the backup process.
Previously, Obnam would continue, ignoring the failure to write. If you
make space in the repository and restart Obnam, it will continue from
the previous checkpoint.

The convert5to6 black box test now works even if run by other people
than liw.

"obnam backup" now uses a single SFTP connection to the backup repository,
rather than opening a new one after each checkpoint generation. Thanks to
weinzwang for reporting the problem.

"obnam verify" now obeys the --quiet option.

"obnam backup" no longer counts chunks already in the repository in the
uploaded amount of data.